The calculations by Ernst & Young (E&Y) came as Prime Minister David Cameron said Britain would veto any attempt to introduce a so-called "Tobin tax", arguing that imposing such a levy across Europe without similar measures being in place elsewhere in the world would hit European jobs and prosperity.

France has indicated that it will push ahead with plans for the tax, but Germany has signalled it wants to build the broadest possible consensus for a levy.

The issue is set to be one of several on the agenda when German chancellor Angela Merkel hosts talks on Monday with French president Nicolas Sarkozy as the pair continue their attempts to tame the eurozone's debt crisis.

But the difficulties of tackling the crisis were illustrated on Sunday amid speculation that private-sector holders of Greek bonds are poised to accept higher losses. They are said to be likely to suffer a haircut of 55pc to 60pc, more than the 50pc agreed in October.

Strategic differences have emerged over plans for a financial transaction tax, under which stock and bond trades would be taxed at the rate of 0.1pc, with derivatives taxed at 0.01pc.

The EU's executive arm, the European Commission, said on Sunday it may push for a tax among a smaller group of members if agreement by all 27 proved impossible. This would be via an "enhanced co-operation" procedure, which requires a minimum of nine countries to agree.

Last September, the Commission published an impact study of the tax, suggesting it could raise annual revenue of around €37bn.

But E&Y claimed this study made a "number of optimistic assumptions about the likely decline in trading activity that would result", as well as failing to account for the fall in other tax revenues that would arise from lower economic growth resulting from less financial activity.

When these factors are taken into account, E&Y calculates that the financial transaction tax could leave a €116bn hole in the region's public finances, representing 1.2pc of the €9.8 trillion in public tax revenues that the European Union generated in 2010.

Marie Diron, economic advisor to E&Y, said: "The Commission's figures in the impact study are not misleading – they do clearly outline where they have made assumptions and what they have left out of the calculations, but the publicised €37bn revenue figure definitely masks the true effect of the tax on EU public finances."